This read-write enabled/disabled flag turns receive-memory thresholding on or off for an individual port, and it is DURABLE so the setting persists across reboots. An admin disables it on ports where receive buffer congestion monitoring isn't useful, or enables it to get congestion alerts on ports carrying important inbound traffic. For example, enabling this on a server-facing port lets the switch track and report when that port's inbound buffer usage becomes excessive.